读完后如何锁定InputStream并释放

Question

I want to put a Lock around java.io.InputStream Object and lock this stream. And when I am done finished reading I want to release the lock. How can I achieve this?

Answer 1

Do you mean?

InputStream is =
synchronized(is) { // obtains lock
    // read is
} // release lock

Its usually a good idea to use one thread to read or write to a stream, otherwise you are likely to get some confusing and random bugs. ;)

If you want to use a Lock as well

InputStream is =
Lock lockForIs = 
lockForIs.lock();
try {
    // read is
} finally {
    lockForIs.unlock();
}

Answer 2

You can't just lock on the InputStream, as it wouldn't prevent write access from a relevant OutputStream; you have to check the lock any time you want to write from the OutputStream.